The night before, move the puff pastry from the freezer to the fridge.

A half hour before you want to serve breakfast, preheat the oven to 400 degrees F.

Unfold the sheet of puff pastry, and cut two diagonal lines from corner to corner to make 4 squares. Line a quarter of the chocolate on the long side of each triangle, and roll up, bending int the corners like a crescent shape. Park the croissants on a Silpat- or parchment-lined baking sheet, and bake 25 to 30 minutes, until puffed and golden. Serve now!